1// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
2// Distributed under the MIT License (http://opensource.org/licenses/MIT)
3
4#pragma once
5
6//
7// Async logging using global thread pool
8// All loggers created here share same global thread pool.
9// Each log message is pushed to a queue along with a shared pointer to the
10// logger.
11// If a logger deleted while having pending messages in the queue, it's actual
12// destruction will defer
13// until all its messages are processed by the thread pool.
14// This is because each message in the queue holds a shared_ptr to the
15// originating logger.
16
17#include <spdlog/async_logger.h>
18#include <spdlog/details/registry.h>
19#include <spdlog/details/thread_pool.h>
20
21#include <memory>
22#include <mutex>
23#include <functional>
24
25namespace spdlog {
26
27namespace details {
28static const size_t default_async_q_size = 8192;
29}
30
31// async logger factory - creates async loggers backed with thread pool.
32// if a global thread pool doesn't already exist, create it with default queue
33// size of 8192 items and single thread.
34template<async_overflow_policy OverflowPolicy = async_overflow_policy::block>
35struct async_factory_impl
36{
37 template<typename Sink, typename... SinkArgs>
38 static std::shared_ptr<async_logger> create(std::string logger_name, SinkArgs &&... args)
39 {
40 auto &registry_inst = details::registry::instance();
41
42 // create global thread pool if not already exists..
43
44 auto &mutex = registry_inst.tp_mutex();
45 std::lock_guard<std::recursive_mutex> tp_lock(mutex);
46 auto tp = registry_inst.get_tp();
47 if (tp == nullptr)
48 {
49 tp = std::make_shared<details::thread_pool>(details::default_async_q_size, 1U);
50 registry_inst.set_tp(tp);
51 }
52
53 auto sink = std::make_shared<Sink>(std::forward<SinkArgs>(args)...);
54 auto new_logger = std::make_shared<async_logger>(std::move(logger_name), std::move(sink), std::move(tp), OverflowPolicy);
55 registry_inst.initialize_logger(new_logger);
56 return new_logger;
57 }
58};
59
60using async_factory = async_factory_impl<async_overflow_policy::block>;
61using async_factory_nonblock = async_factory_impl<async_overflow_policy::overrun_oldest>;
62
63template<typename Sink, typename... SinkArgs>
64inline std::shared_ptr<spdlog::logger> create_async(std::string logger_name, SinkArgs &&... sink_args)
65{
66 return async_factory::create<Sink>(std::move(logger_name), std::forward<SinkArgs>(sink_args)...);
67}
68
69template<typename Sink, typename... SinkArgs>
70inline std::shared_ptr<spdlog::logger> create_async_nb(std::string logger_name, SinkArgs &&... sink_args)
71{
72 return async_factory_nonblock::create<Sink>(std::move(logger_name), std::forward<SinkArgs>(sink_args)...);
73}
74
75// set global thread pool.
76inline void init_thread_pool(
77 size_t q_size, size_t thread_count, std::function<void()> on_thread_start, std::function<void()> on_thread_stop)
78{
79 auto tp = std::make_shared<details::thread_pool>(q_size, thread_count, on_thread_start, on_thread_stop);
80 details::registry::instance().set_tp(std::move(tp));
81}
82
83inline void init_thread_pool(size_t q_size, size_t thread_count, std::function<void()> on_thread_start)
84{
85 init_thread_pool(q_size, thread_count, on_thread_start, [] {});
86}
87
88inline void init_thread_pool(size_t q_size, size_t thread_count)
89{
90 init_thread_pool(
91 q_size, thread_count, [] {}, [] {});
92}
93
94// get the global thread pool.
95inline std::shared_ptr<spdlog::details::thread_pool> thread_pool()
96{
97 return details::registry::instance().get_tp();
98}
99} // namespace spdlog
100